Experiences? I've been on this for about a week, now. The first 4-5 days were fine, but the last few I've felt just meh. Not sure if it's the hormones or possibly that I started new asthma meds (was on Qvar and am now on Symbicort, which is similar + long-acting bronchodilator). Or maybe I'm coming down with a cold. Several cycling friends have been sick and I wonder if I'm battling one of their bugs. And it's rained pretty much every day for the past week, so I suspect mold is an issue, as well (still have to have deep-skin testing for grass, trees, mold, but my mom is allergic to mold and I've got all of her other allergens confirmed via previous tests).
I've also had a bit of vertigo...which could be a side-effect or it could be vertigo for no good reason. I suffer with this at random and have for years -- likely related to my allergy/sinus/asthma issues. Totally irritating.
I've read that the first few cycles on Prometrium can be rough, since the body's initial reaction is to pump out more estrogen (the point of taking progesterone is to help balance things, since I've been "estrogen dominant" for a while). I'm hoping that I'm not going to have a week or more of this every 28 days! But I guess it beats 8-13 days of bleeding every 21-23 days....